This report focuses on Interpersonal Influence (INF), an instructional system developed by the Improving Teaching Competencies Program at the Northwest Regional Educational Laboratory. The stated purpose of the system is to provide classroom teachers with a set of skills and concepts that can help them engage in productive, collaborative efforts and understand interpersonal and group processes within their own schools and classrooms. Three evaluative studies are discussed. One of the studies focuses on short-term cognitive and affective effects, one on impact of teachers' training on the classroom, and one on the appropriateness of the system for potential consumers. The first section of this report includes a description of the INF instructional system. The design of the field test, which assessed short-term effects of the system, is presented in section two, while section three includes a description of the results of the field test study. The design of the impact study, which determined the effects of training on student reports of classroom climate, is presented in section four. Section five contains the results and discussion of the impact study. Section six presents the design used in the expert review of INF, while section seven discusses results of the review. Section eight includes recommendations based on the results of the studies presented in this report. The appendixes include field test instruments, questionnaires, inventories, and letters. A summary of this report is also included. (RC)